1, the sphygmomanometer wind be on the left wrist;2, the strap around from the palm to the wrist at a distance 10-15MM (ie a finger width);3, please do not put the cuffs volumes residing;4, holding the lower end of the strap on the wrist while pulling close to the volume, if not snapping may cause measurement error is too large;5, the remaining part of the strap folded roll is good, then the lower strap will not cause a burden;6. Please use the right measure also repeat the same action, but the choice of the left hand because the left-handed closer from the heart, it is strongly recommended to measure, in order to reduce errors;7, the height of the wrist strap with heart (nipple position) the same.Medical tests proved: a normal person, the day of the blood pressure is fluctuating, human blood pressure lowest at 8:00 to 10:00 highest blood pressure, normal day, systolic blood pressure (hypertension) changes in the magnitude of 20 to that during sleep between 40mmHg, diastolic blood pressure (low pressure) changes in the range between 10 to 20mmHg, even at night, people sleep, there are 5 to 10mmHg fluctuating. In fact electronic sphygmomanometer measured value reflects the value of the human blood pressure measurement time. Human blood pressure is constantly changing, the two measurements to obtain the same blood pressure value is very rare. Therefore, only a day at the same time, with the same posture measuring blood pressure, blood pressure to get comparable value.